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[ES] En el presente proyecto se desarrolla el diseño de la geometría del chasis monocasco para el prototipo FSUPV ¿ 09 y FSUPV ¿ 010. El principal objetivo del nuevo diseño es: adaptarse a las necesidades a las necesidades de los distintos subsistemas del vehículo, enfatizando en la aerodinámica, la ergonomía del piloto y las necesidades del sistema autónomo. Al mismo tiempo, para garantizar que las propiedades mecánicas de la pieza son la idóneas. Se han desarrollado en paralelo la composición de las capas de la estructura tipo sándwich de CFRP y core de honeycomb de aluminio. Mediante el uso de análisis por elementos finitos y ensayos controlados. También se analizaran el proceso de fabricación, así como el impacto en el comportamiento del monoplaza., [EN] In this project, the design of the geometry of the monocoque chassis for the prototype FSUPV ¿ 09 and FSUPV ¿ 010 is developed. The main objective of the new design is: to adapt to the needs of the different subsystems of the vehicle, emphasizing the aerodynamics, pilot ergonomics and the needs of the autonomous system. At the same time, to guarantee that the mechanical properties of the part are ideal. The composition of the layers of the CFRP sandwich structure and aluminum honeycomb core have been developed in parallel. Through the use of finite element analysis and controlled trials. The manufacturing process will also be analyzed, as well as the impact on the behavior of the car.

The monocoque is a chassis that represents the skeleton of a racing vehicle, this is the largest structure present within it, where all the components are mounted, as well as, all the loads are transmitted. In this work, this structure is formed by sandwich panels, which are generally used in motorsport areas, as well as in transportation vehicles where high rigidity is associated with low weight, these types of panels have two outer faces with a core in the middle. The present work is done around a chassis for a formula student electric vehicle for the FSIPLeiria team, where the goal is, through the analysis of the various panels, according to the competition rules, and the finite element analysis, to obtain a rigid structure that complies with the regulations and will be able to compete in the future, then a project of the monocoque geometry was designed, for the analysis of the dynamic loads, at the suspension attachment points, and torsional stiffness in order to optimize the structure’s composition. It was possible to conclude that the monocoque is a superior structure to a conventional tubular chassis, made from steel tubes, in terms of bending and torsional stiffness, however, these advantages come at a cost due to the complexity during the whole development process, as well as in production and in monetary costs.

Purpose There are over 40 million amputees globally with more than 185,000 Americans losing their limbs every year. For most of the world, prosthetic devices remain too expensive and uncomfortable. This paper aims to outline advancements made by a multidisciplinary research group, interested in advancing the restoration of human motion through accessible lower limb prostheses. Design/methodology/approach Customization, comfort and functionality are the most important metrics reported by prosthetists and patients. The work of this paper presents the design and manufacturing of a custom made, cost-effective and functional three-dimensional (3D) printed transtibial prosthesis monocoque design. The design of the prosthesis integrates 3D imaging, modelling and optimization techniques coupled with additive manufacturing. Findings The successful fabrication of a functional monocoque prosthesis through 3D printing indicates the workflow may be a solution to the worldwide accessibility crisis. The digital workflow developed in this work offers great potential for providing prosthetic devices to rural communities, which lack access to skilled prosthetic physicians. The authors found that using the workflow together with 3D printing, this study can create custom monocoque prostheses (Figure 16). These prostheses are comfortable, functional and properly aligned. In comparison with traditional prosthetic devices, the authors slowered the average cost, weight and time of production by 95%, 55% and 95%, respectively. Social implications This novel digital design and manufacturing workflow has the potential to democratize and globally proliferate access to prosthetic devices, which restore the patient’s mobility, quality of life and health. LIMBER’s toolbox can reach places where proper prosthetic and orthotic care is not available. The digital workflow reduces the cost of making custom devices by an order of magnitude, enabling broader reach, faster access and improved comfort. This is particularly important for children who grow quickly and need new devices every few months or years, timely access is both physically and psychologically important. Originality/value In this manuscript, the authors show the application of digital design techniques for fabricating prosthetic devices. The proposed workflow implements several advantageous changes and, most importantly, digitally blends the three components of a transtibial prosthesis into a single, 3D printable monocoque device. The development of a novel unibody transtibial device that is properly aligned and adjusted digitally, greatly reduces the number of visits an amputee must make to a clinic to have a certified prosthetist adjust and modify their prosthesis. The authors believe this novel workflow has the potential to ease the worldwide accessibility crisis for prostheses.

A carbon fibre reinforced polymer is designed for NACA0012 airfoil wing using a finite element model to determine the stresses and deformation by considering the aerodynamic loads from wind tunnel testing. The composite airfoil is designed for the use in morphing wings which are known to increase the aerodynamic efficiency of unmanned aerial vehicles. This paper deals with the design procedures of modelling a composite wing using different design variables in conformance to the first order shear deformation theory using ANSYS® 19.2 and optimizing the design by using a fourth degree polynomial found by surface fitting and genetic algorithm in MATLAB® R2020a. The analysis is carried out on 125 samples consisting of different materials, orientation and thickness. The pressure loads found from the wind tunnel testing was converted using weighted average method and applied in ANSYS® 19.2. While designing the airfoil, monocoque concept is used for structural integrity and this is implemented by the usage of Styrene acrylonitrile at the leading and trailing edges which has high strength to weight ratio. The composite laminae with a certain orientation and thickness is found to have the lowest deformation of 158 nm in response to the aerodynamic load.

This paper deals with the design of a multi-part mould for the production of a carbon fibre medium-large compo-nent. The design and forming of a medium-large component which is defined by a closed structure and has high demands on dimensional accuracy is a very complex process. The goal was to design a simple manufacturing pro-cess for a negative mould. There are many different ways to design and manufacture this type of mould. One pos-sible solution was designed and tested. This paper describes the case study of a carbon fibre monocoque of a small racing car. The first step was to define the requirements of the final product and the negative mould. The next step was to design a multi-part mould with one main parting plane and two minor parting planes and define the number of steps needed to build a negative mould. Another problem is how to define the position of the general anchor points that determine the final product. In this case the procedure of transferring the hole from a positive to a negative mould was defined.

This paper proposes a novel design methodology for electric-bus structures by implementing the finite element method via ABAQUS™ and linear programming via MATLAB™. A monocoque sandwich-structured fiber-reinforced composite bus with a maximum driving range of 300 km is conceived using the proposed methodology. The bus-body structure is designed based on safety criteria such as vehicle registration regulations, the strength of the bus structure under various driving conditions, bending- and torsion-stiffness requirements, and the rollover testing standard of UN ECE R66. A procedure developed to systematically conduct parametric studies by varying the core and face thicknesses of the sandwich structure of each component is presented. Multivariate functions are formulated to determine the correlations of structural responses with changes in geometric parameters. Linear programming is implemented to minimize the mass of the bus structure under design constraints. The proposed monocoque bus structure meets all requirements, and its body mass is 63.3% less than the benchmark value.

Chassis is an integral part of any automobile. Chassis is solely responsible for bearing the entire vehicle's weight along with the payload. In today's industry, three most common types of chassis used are Ladder-frame chassis, Monocoque chassis and Spaceframe chassis. Ladder-frame chassis finds its use in most of the heavy weight vehicles, trucks and busses, whereas, monocoque and spaceframe chassis find their application in light commercial vehicles. This paper specifically talks about the ladder-fame chassis. Since the chassis is an integral part of any vehicle, the weight of chassis plays a significant role in determination of entire vehicle's weight which in turns affects many parameters related to the performance of the vehicle. Most of the industries use steel alloys to construct these chassis which in turn make the vehicle heavy. Modern advancements in Material Sciences has suggested use of Carbon Reinforced Epoxy based Polymeric Composites instead of Steel alloys for the manufacturing of these chassis. Carbon Reinforced Epoxy based Polymeric Composites are basically made of two components, viz, Carbon and Epoxy and the variation in volumetric composition of each, leads to significant changes in significant mechanical properties of the composites. This paper deals with the determination of exact volumetric composition of Carbon and Epoxy in Carbon Reinforced Epoxy based Polymeric Composites which would ultimately replace the existing steel alloys with the help of stimulation software, ANSYS. This paper also determines the exact cross-section of the chassis made with Carbon Reinforced Epoxy based Polymeric Composites which could eliminate the steel alloy chassis with existing cross-sections

[ES] El presente documento pretende recopilar y evaluar los procesos actuales de fabricación y diseño de los moldes para la fabricación de un chasis tipo monocasco en materiales compuestos de un monoplaza tipo formula student. Así como de proponer métodos innovadores de fabricación del molde a través de tecnología de impresión 3D en materiales compuestos reciclables como la fibra de carbono con matriz ABS para la reducción de los tiempos totales y reducción de los residuos finales. Para ello el proyecto recopila además los desarrollos e investigación necesarias para la correcta producción futura de un molde por impresión 3D en material compuesto termoplástico. El producto final, por tanto, debe cumplir las características de resistencia mecánica, térmica, acabado y tolerancias superficiales que permitan la correcta fabricación y tolerancias finales deseadas para el correcto desarrollo del monoplaza así como sea compatible con los tiempos de fabricación y capacidades del FSUPV Team, equipo de formula student de la Universidad Politécnica de Valencia., [CAT] El present document pretén recopilar i avaluar els processos actuals de fabricació i disseny dels motles per a la fabricació d'un xassís tipus monobuc en materials compostos d'un monoplaça tipus formula student. així com de proposar mètodes innovadors de fabricació del motle a través de tecnologia d'impressió 3D en materials compostos reciclables com la fibra de carboni amb matriu ABS per a la reducció dels temps totals i reducció dels residus finals. Per a això el projecte recopila a més els desenvolupaments i investigació necessàries per a la correcta producció futura d'un motle per impressió 3D en material compost termoplàstic. El producte final, per tant, ha de complir les característiques de resistència mecànica, tèrmica, acabat i toleràncies superficials que permeten la correcta fabricació i toleràncies finals desitjades per al correcte desenvolupament del monoplaça, així com siga compatible amb els temps de fabricació i capacitats del FSUPV Team, equip de formula student de la Universitat Politècnica de València., [EN] This document aims to collect and evaluate the current processes of manufacturing and design of molds for the manufacture of a monocoque-type chassis in composite materials for a single-seater formula student type. As well as proposing innovative mold manufacturing methods through 3D printing technology in recyclable composite materials such as carbonfiber with an ABS matrix to reduce total times and reduce final waste. For this, the project also compiles the developments and research necessary for the correct future production of a 3D printing mold in composite material. thermoplastic. The final product, therefore, must meet the characteristics of mechanical and thermal resistance, finish and surface tolerances that allow the correct manufacturing and desired final tolerances for the correct development of the single-seater as well as being compatible with the manufacturing times and capabilities of the FSUPV Team. , formula student team of the Universitat Politècnica de Valencia.

An introduction to the structural layout of conventional GA aircraft is provided. Special mentioning of aircraft loads is made to help the student understand how different parts of the aircraft structure are designed to react a specific type of load. Then, information on the characteristics and properties of typical materials used for the construction of the modern GA aircraft. This includes aluminum, steel, titanium, and composite materials. The last section of the chapter presents a description of the fabrication of and installation of various structural components for aircraft, such as the fuselage, wing, and stabilizing surfaces.

Tema diplomskog rada je „Primjena kompozitnih materijala u izradi bolida Formule 1”. Kompoziti se proizvode umjetnim spajanjem s najmanje dva različita materijala s ciljem dobivanja materijala takvih svojstava kakva ne posjeduje niti jedna komponenta sama za sebe. U uvodnom dijelu opisani su ukratko kompozitni materijali, a zatim slijedi povijesni tijek kao i detaljan opis podjele kompozitnih materijala. Centralni dio ovog diplomskog rada obuhvaća primjenu kompozitnih materijala u Formuli 1. Prvo je opisana povijest Formule 1, a zatim su opisani dijelovi bolida, a to su sigurnosna kapsula tj. monocoque, pogonski sklop, kočioni sistem, spremnik goriva, ovjes, pneumatici i aerodinamika. Sva pravila koja se odnose na utrku F1, sigurnost vozača, konstrukciju i dizajn bolida, donosi organizacija FIA. Pravila su se mijenjala tijekom godina, a napredak je ogroman što je vidljivo uspordbom bolida kroz povijest. Zadnji dio ovog diplomskog rada prikazuje izradu šasije bolida Formule Student gdje se može vidjeti razlika između bolida F1 i Formule Student. U radu je opisana šasija bolida koje su izrađivali Hrvatski studenti iz FSB Racing Teama. Nakon svega slijedi zaključak koji sadrži navedena saznanja tijekom pisanja ovog diplomskog rada., The topic of the thesis is „Formula 1 applications of composite materials”. Composites are produced by artificially joining at least two different materials with the aim of obtaining materials with such properties that no single component has on its own. Composite materials are briefly described in the introductory part, followed by the historical course as well as a detailed description of the division of composite materials. The central part of this thesis covers the application of composite materials in Formula 1. Firstly, the history of Formula 1 is described, and then the parts of the car are described, namely the safety capsule i.e. the monocoque, powertrain, brake system, fuel tank, suspension, tires and aerodynamics. All rules related to the F1 race, driver safety, construction and design of the car are adopted by the FIA organization. The rules have been changed over the years, and huge progress has been made, which can be seen by comparing cars throughout history. The last part of this thesis shows the creation of the Formula Student car chassis, where you can see the difference between the F1 and Formula Student cars. The paper describes the chassis of the cars made by Croatian students from the FSB Racing Team. To conclude, the last section clarifies the knowledge obtained during the writing of this thesis.

Lately, numerous studies have been performed to design composite monocoque’s with high strength and low weight for various student-level racing contests. The objective of this paper is to develop an insightful methodology to design and developed a lightweight composite monocoque. The monocoque is designed to pass the mandatory static load tests laid down by the International Automobile Federation (FIA) Formula 3. These Formula 3 tests are considered the baseline of the desired structural integrity of the composite monocoque. The presented design technique emphasizes on a monocoque developed for Sports Car Club of America races. The three standard load tests performed on the monocoque are survival cell side test, fuel tank test and side intrusion test. A sandwich layup of bidirectional-woven carbon/epoxy prepreg and aluminum honeycomb is optimized for minimum weight while predicting the unknown properties of layup, and ensuring the monocoque does not experience failure. The approach intends to achieve minimum weight with high torsional rigidity and is capable of being used for the design and analysis of any kind of formula-type composite monocoque.

A finite element model is developed to determine deformation and stresses on a composite wing of unmanned aerial vehicle (UAV) with a tubercle design at the leading edge of the wing. Tubercles, commonly known as protuberances found on the leading edge of a whale pectoral flipper, offering great performance from an aerodynamic perspective. This paper deals with a first order shear deformation theory (FSDT) approach to discover the UAV laminates composite wing model of tubercle leading edge (TLE) with rib-reinforced so that the equivalent stiffness and material properties are obtained from the simulation of finite element analysis using ANSYS. Another structural configuration of design replicating the idea of monocoque concept, whereby foam is used at the leading and trailing edges of the wing. Styrene acrylonitrile (SAN) core foam is used representing high strength-to-weight ratio with its superiority in the mechanical properties of polymeric sandwich composites. The updated static structural analysis from rib-reinforced can be applied to update the wing stiffness distribution of monocoque-foam. The optimum design is concluded from the tabulated deformation and stresses of both wings, where monocoque-foam showed better performance with a reduction in 50.72% of deformation and 35.88% of stress, compared to rib-reinforced design. Keywords: Laminates composite wing, Rib-reinforced, Monocoque-foam, Finite element analysis

This work focuses on the suspension attachment area of FST Lisboa’s formula student monocoque chassis, analysing two types of reinforcements, inserts and chamfers, changing some of their parameters for geometry improvement. A finite element model was built in order to set the comparison between the different geometries, first separately and then when included in a suspension quarter-car assembly. The geometries with best results were selected and a laminate layup optimization was made. Lastly, for validation of the numerical model, four specimens of each one of the two approaches were built and a pull-out test was performed on them, with a custom developed apparatus. Failure modes, similar to those previewed by theory, were achieved and a finest correlation between the experimental and numerical results was found for inserts, better than for chamfers, mostly due to manufacturing difficulties. The obtained results and conclusions were applied in the design and construction of the team’s new prototype monocoque.

A multiple criteria decision methods (MCDM) using Complex Proportional Assessment (COPRAS), Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), and Cost per Unit Property were utilized to determine the best material in the design of monocoque for a fuel efficient vehicle. Specifically, the material properties being evaluated from the different alternative materials for the floorboard and body of an urban concept eco-car underwent necessary calculations based on the integration of the various material selection methods. The study showed that the glass fiber-reinforced polymer (GFRP) was the best floorboard material among other options from magnesium alloys, aluminium alloys, mild steel and carbon fiber-reinforced polymer (CFRP). The criteria considered in the calculation include the ultimate strength, yield strength, modulus of elasticity, density and cost. Moreover, the face sheet CFRP and honeycomb core sandwich combination, particularly the T700-Nomex honeycomb, was the best option for the car body. The properties being considered in this calculation were the maximum in plane stress (MIPS) of the face sheet material, the maximum shear stress of the core, the weight and the cost.

This paper focuses on the use of Carbon-Reinforced Epoxy based Polymeric Composite Tubes in place of regular AISI 4130 tubes used in manufacturing of the space-frame chassis of a car. The Automobile industry uses basically three types of chassis, viz, Space-frame chassis, Monocoque chassis and Ladder-frame chassis. The Chassis under study is chassis of an All-Terrain Vehicle and all the calculations and results are done with the help of ANSYS . The paper is basically divided into two parts. The first part deals with the variation of the composition of carbon and epoxy in the polymeric composite tubes and finding out the most accurate composition, which could be used to replace the existing material. The Second parts deals with the variation in the dimensions of the cross-sections of the tube and finding the most accurate dimension which could give competition to the existing norms. The major deciding factor taking in consideration was the maximum deflection observed under basic loading conditions. The paper concludes by comparing the weight of both the chassis, one using AISI 4130 tubes and one using Carbon-Reinforced Epoxy based Polymeric Composite Tubes.

Along with the development of new structural materials, the study of novel manufacturing techniques becomes necessary to improve their performance and achieve optimal mechanical resistance thresholds. The present paper deals with the expedients and precautions necessary to avoid the formation of defects on carbon fiber reinforced polymers manufactured over a high-density polyurethane (PU) foam pattern. Particularly, for the attainment of a deffect-free monocoque structure for an innovative solar vehicle. The experimental campaign carried is hereby described where foam pre-treatment steps were thoroughly explored in terms of sanding and application of chemicals such as release agents and sealer. Overcoming the inherent challenge of using a yet undiffused and little known pattern material, successful results have been attained.

Aquest projecte s’ha dut a terme amb l’objectiu de desenvolupar un nou disseny de xassís monocasc amb una estructura de “Sandwich” amb compòsits com un pas endavant respecte del xassís d’acer tubular actual que utilitza l’equip de Fórmula Student, Dynamics UPC Manresa. Aquest canvi de tipologia de xassís, és degut a que en l’automobilisme de competició és necessari utilitzar els materials tecnològicament més avançats per estar al més alt nivell. Així doncs, en primer lloc s’explica en què consisteixen els materials compostos que s’utilitzen en aquests tipus d’estructures i conèixer com afecta la seva disposició a l’hora de dissenyar el xassís de forma òptima. Posteriorment, s’argumenta el disseny de la geometria el qual depèn majoritàriament de les limitacions imposades per la normativa de Fórmula Student i també per les necessitats dels altres departaments de l’equip. Per últim la geometria serà sotmesa a diferents simulacions FEM per tal d’optimitzar el pes total del monocasc afectant el mínim possible la seva rigidesa estructural. En definitiva el resultat final és un xassís optimitzat on s’aconsegueix la màxima baixada de pes augmentat relativament poc el desplaçament, ja que és el que es busca en els vehicles de competició, i alhora que les diferents capes resultants d’aquesta optimització seran simples perquè el monocasc es pugui fabricar correctament amb els recursos dels quals disposa l’equip. This project has been carried out with the aim of developing a new monocoque chassis design with a composite material sandwich structure as a step forward compared with the current tubular steel chassis used by the Formula Student team, Dynamics UPC Manresa. This change in the chassis topology is due to the necessity of using the more technological evolved materials as the motorsport is a very competitive and the teams need to be at the highest level. So, first it is explained what the composite materials used in these types of structures consist of and to know how their layup affects when designing the chassis optimally. Subsequently, the design of the geometry is argued, which largely depends on the limitations imposed by the Formula Student regulations and also on the needs of the other departments of the team. Finally, the geometry will be subjected to different FEM simulations in order to optimize the total weight of the monocoque, affecting as little as possible its structural rigidity. To sum up, the final result is an optimized chassis achieving the maximum weight loss increasing relatively not much displacement, as it is what is sought in competition vehicles, and at the same time the different plies of this optimization will be simple so that the monocoque can be manufactured properly with the resources available to the team.

The main aim of this study is to produce the improved topology of a solar car monocoque in order to reduce its weight. Therefore, this paper analyzes these 3rd generation solar car (Tigris) monocoque structural integrity, cost and power consumption. Finite element analyses were performed to simulate the deformation and generate the stress contour of the solar car monocoque. Cost and power consumption were calculated using theoretical methods. Finally, the results from the current study are compared to the previous solar cars (Stingray and Tuah). Prior to that, mesh convergence analysis and numerical validation were performed. In terms of reducing weight, the results show that the strength of the current monocoque is comparable to the previous monocoques, even it used less materials and parts. The study also suggests that the cost of fabrication of the current monocoque can be reduced up to 27% while the power consumption can be reduced up to 28%. Due to the generated data and deduced findings, it can be concluded that the current study is useful and has contributed knowledge about designing and analyzing the structural integrity, cost and power consumption of a solar car monocoque.

[ES] Formula Student es una competición global en la que la que equipos formados por estudiantes diseñan, construyen y testean un monoplaza tipo fórmula con el objetivo de competir entre ellos en diferentes competiciones por los mejores circuitos del mundo, midiéndose en diferentes pruebas, este trabajo se ha realizado en el equipo de Formula Student de la Universitat Politècnica de Valencia, el FSUPV Team. El propósito de este trabajo es el de diseñar una estructura que sea unión de las dos partes del monocasco en la zona trasera del mismo donde por cuestiones de ensamblaje la sección es abierta y que sirva de anclaje para el motor, un Honda CBR 600 RR, para los amortiguadores y para los porta-diferenciales que como su propio nombre indica dan anclaje al diferencial, el cual mediante la cadena y a través de la corona recibe el par del motor. La dificultad de esta pieza reside en hacerla en aluminio a diferencia de la tubular de acero que se tenía anteriormente, teniendo que lidiar con el riesgo de su fallo a fatiga, al ser una estructura que ve un conjunto de cargas complejo, de elevado orden y de un alto número de ciclos. El flujo de diseño comenzara con un análisis de los requerimientos geométricos que ha de cumplir la pieza, posteriormente se pasará su optimización mecánica por medio de la simulación en el software SolidWorks y por último se hará un análisis de resultados de la mejor versión obtenida y la que a posteriori ha sido mecanizada para su ensamblaje en el prototipo. También se abordan en este trabajo la realización de ensayos no destructivos como son el análisis de vibraciones, puesto que es una pieza situada en el punto más crítico del coche en cuanto a estas y la inspección por líquidos penetrantes a diferentes kilómetros de vida para la validación de su resistencia a la fatiga., [CA] Formula Student és una competició global en la qual la que equips formats per estudiants dissenyen, construeixen i testen un monoplaça tipus fórmula amb l'objectiu de competir entre ells en diferents competicions pels millors circuits del món, mesurant-se en diferents proves, aquest treball s'ha realitzat en l'equip de Formula Student de la Universitat Politècnica de València, el FSUPV Team. El propòsit d'aquest treball és el de dissenyar una estructura que siga unió de les dues parts del monocasc en la zona posterior del mateix on per qüestions d'assemblatge la secció és oberta i que servisca d'ancoratge per al motor, un Honda CBR 600 RR, per als amortiguadors i per als porta-diferencials que com el seu propi nom indica donen ancoratge al diferencial, el qual mitjançant la cadena i a través de la corona rep el parell del motor. La dificultat d'aquesta peça resideix a fer-la en alumini a diferència de la tubular d'acer que es tenia anteriorment, havent de bregar amb el risc de la seua fallada a fatiga, ja que és una estructura que veu un conjunt de càrregues complex, d'elevat ordre i d'un alt nombre de cicles. El flux de disseny començarà amb una anàlisi dels requeriments geomètrics que ha de complir la peça, posteriorment es passarà la seua optimització mecànica per mitjà de la simulació en el programa SolidWorks i per últim es farà una anàlisi delsresultats de la millor versió obtinguda i la que a posteriori ha sigut mecanitzada per al seu assemblatge en el prototip. També s'aborden en aquest treball la realització d'assajos no destructius com són l'anàlisi de vibracions, ja que és una peça situada en el punt més crític del cotxe quant a aquestes i la inspecció per líquids penetrants a diferents quilòmetres de vida per a la validació de la seua resistència a la fatiga., [EN] Formula Student is a global competition in which teams formed by students design, build and test a formula car with the aim of competing against each other in different competitions on the best circuits in the world, measuring themselves in different tests. This work has been carried out in the Formula Student team of the Universitat Politècnica de Valencia, the FSUPV Team. The purpose of this work is to design a structure being the union of the two parts of the monocoque in the rear area where for assembly issues the section is open and also being attachment for the engine, a Honda CBR 600 RR, for the dampers and for the differential, which by means of the chain and through the crown receives the torque from the engine. The difficulty of this part lies in making it in aluminium as opposed to the tubular steel that was previously used, having to deal with the risk of fatigue failure, being a structure that sees a complex set of loads, high order and a high number of cycles. The design flow will begin with an analysis of the geometric requirements that the part has to meet, followed by its mechanical optimisation by means of simulation in SolidWorks software and finally an analysis of the results of the best version obtained and the one that has been subsequently machined for assembly in the prototype. This work also includes the performance of non-destructive tests such as vibration analysis, since this is a part located at the most critical point of the car in terms of vibrations, and inspection by penetrating liquids at different kilometres of life to validate its resistance to fatigue.

Tento článek se zabývá srovnáním experimentálního měření a numerické simulace vlastní frekvence a přirozeného tvaru monokoku z uhlíkových vláken. Toto srovnání se používá k ověření numerické analýzy se skutečným monokokem. Obvykle se monokoky skládají z ortotropních materiálů, jako je sendvič z uhlíkových vláken s voštinovým jádrem. Monokok je vyráběn ručně z několika vrstev různých materiálů, které jsou spojeny lepenými spoji. To nezaručuje materiálové vlastnosti nebo stejnou hmotnost jako idealizovaná numerická simulace. This paper deals with the comparison of experimental measurements and numerical simulation of the natural frequency and natural shape of a carbon fibre monocoque. This comparison is used to validate the numerical analysis with a real monocoque. Usually, monocoques consist of orthotropic materialslike carbon fibre sandwich with a honeycomb core. The monocoque is manufactured by hand from several layers of different materials, which are connected by glued joints. This does not guarantee the material properties or the same mass the idealized numerical simulation.

Composite materials made with the objective of getting a more desirable combination of properties are extensively used in weight-sensitive structures due to its very high strength to weight ratio and relatively high stiffness to weight ratio. A payload adapter forms an interface between the payload or the satellite and the launch vehicle core. The importance of weight savings in the payload adapter is that any reduction in its mass can help in a corresponding increase in the satellite mass since the sensitivity is 1:1. This is due to the positioning of the payload adapter near the satellite. This paper deals with the optimal design of a lightweight Composite Payload Adapter in three different configurations with a maximum mass advantage which at the same time should be able to withstand the loads acting on them during the flight. The design options studied were: monocoque, stringer-stiffened, and sandwich-structured construction. In monocoque construction, a metallic skinned structure made out of aluminium and also layered composite skinned structure made out of M55J/M18 prepreg laminates are considered for the study. The sandwich constructions are studied with metallic face sheets and layered composite face sheets in combination with a hexagonal aluminium honeycomb core. The study of stringer-stiffened construction was conducted by comparing the structure having the stringers and the shell made of aluminium with that made of M55J/M18 laminates. The optimum design out of these cases studied was arrived at. Static, buckling and free vibration analyses of all the cases were carried out using the general-purpose finite element software MSC. NASTRAN.

Diese Arbeit befasst sich mit dem Entstehungsprozess eines Monocoques in Sandwichbauweise, für ein Rennfahrzeug des TUW-Racing. In diesem Produktentwicklungsprozess werden die Konzepterarbeitung, Konstruktion, Optimierung, Fertigung und Validierung behandelt. Die Konzeptphase wird mittels Paarweisevergleich und Nutzwertanalyse unterstützt, um die Umgebung für eine objektive Entscheidungsfindung zu schaffen. Aus diesem entstehen Konzeptvorschläge, die dem TUW-Racing bereitgestellt werden, um ein Lastenheft zu erstellen. Auf Grund der definierten Konzepte und Regeln des Formula Student entsteht die Außenform der Karosserie. Das Hauptaugenmerk der Arbeit liegt aber auf der Optimierung der Sandwichstruktur. Dabei soll eine Torsionssteifigkeit von 2500 bis 3000Nm/°, bei einer minimalen Masse erreicht werden. Hierfür wird eine Finite-Elemente-Software verwendet. Abschließend wird das gefertigte Monocoque einer Torsionssteifigkeitsmessung unterzogen, um die errechneten Werte zu validieren. Das fertige Produkt besitzt ohne Anbauteile eine Masse von 20,7kg und eine Torsionssteifigkeit von 2412Nm/°. Mit Anbauteilen wird eine Steifigkeit von 2837Nm/° erreicht., This thesis deals with the development process of a monocoque in sandwich design, for a racing car of the TUW-Racing. The process goes through the concept development, design phase, optimization, manufacturing, and validation of the product.The concept phase is supported by the Pair-By-Pair comparison and the Utility Analysis to create an environment for objective decision making. This process creates suggestions for concept variants and can be considered by the TUW-Racing to create the Technical Specification Sheet. The shape of the chassis is based on the defined concepts and the rules of the formula student. The main focus of this thesis is the optimization of the sandwich structure. Thereby a torsional stiffness of 2500 to 3000Nm/° should be achieved by simultaneous minimization of the weight. Therefore a Finite Element Analysis is used. Conclusively the torsional stiffness of the monocoque is validated through an experimental setup.The final product, without additional components, weighs 20,7kg and achieves a torsional stiffness of 2412Nm/°. The torsional stiffness with additional structures reaches 2837Nm/°.

This article presents further results of the research of effects of model defects on the local buckling of compressed stiffeners in nonlinear finite element (FE) analyses. The main outcomes are confirmation of trends for 10 sets of profile dimensions, final validations of various sets of FE simulations, and designs of practical types of defects with appropriate ratio values. A single node defect and then complex types of defects with alternating distributions of node shifts along one edge, two free flange edges, one flange surface and both flange surfaces are analyzed in this research project. First parts of this paper describe designed FE models with defects, their effects on simulation results, colored graphic visualizations with stress scales and determinations of the sudden failure of stability in the local mode. Then, particular results of FE analyses are validated by a comparison with the results of analytical methods of stability failure. Final detail comparisons of analytical and FE simulation results with data of experimental tests confirm predicted critical buckling forces. The validation of results and design parameters together with the knowledge of effects of model defects on buckling behaviors allows more accurate simulations of internal stiffeners of thin-walled semi-monocoque structures. First published online 29 January 2020

Formula Student es una competición internacional de ingeniería en que las universidades compiten para crear el monoplaza más rápido, barato y fiable. Para cumplir este objetivo, los equipos trabajan duro en sus diseños, fabricación y pruebas a fin de mejorar el comportamiento de su vehículo en la pista, de modo que el consumo de combustible y el coste se reduzcan mientras la velocidad, dinámica lateral y longitudinal y aerodinámica mejoren. Una forma directa de obtener estos resultados es reduciendo el peso del coche tanto como sea posible. Es importante utilizar estructuras ligeras en términos de rendimiento del vehículo, lo que generalmente implica estructuras monocasco basadas en materiales de alta relación resistencia-peso, como matrices poliméricas reforzadas con fibra de carbono (CFRP). En este estudio se ha propuesto una estructura monocasco formada por paneles tipo sándwich fabricados con una lámina superior e inferior de fibra de carbono con matriz epoxi y un núcleo de espuma colocado entre ellos, aumentando el momento de inercia del área de la estructura y mejorando la resistencia del panel. La rigidez torsional del chasis final se ha evaluado utilizando un Modelo de Elementos Finitos (MEF), así como ensayos físicos representativos de los paneles laminados para cumplir con los requisitos de las normas de Formula Student Germany y para garantizar la seguridad de los pilotos. Formula Student is an international engineering competition on which Universities compete to create the fastest, cheapest, and most reliable single-seated and open-wheeled car. In order to fulfill this objective, teams work hard on their designs, manufacturing and testing in order to improve the behaviour of their Formula Student cars on the track so the fuel consumption and cost reduces while velocity, lateral and longitudinal dynamics, and aerodynamics improves. A direct way to get that is by reducing the weight of the car as much as possible. Lightweight structures are important in terms of vehicle performance, and that usually implies monocoque structures based on high strength-to-weight ratio materials as Carbon Fiber Reinforced Plastics (CFRP). In this study, it has been proposed a monocoque structure based on sandwich composite panels made of an upper and a lower facesheet of epoxy reinforced carbon fiber with a foam core placed between them, increasing the area moment of inertia of the structure and improving the strength of the panel. Torsional stiffness of the final chassis has been evaluated by using FEM as well as physical representative tests of the laminated panels to fulfill the requirements of Formula Student Germany rules and to ensure safety for the drivers.

Using the example of testing a monocoque made of polymeric composite material (PCM), this paper considers a sequence of actions in the development of a chassis of a car of the Formula Student class from new materials. The testing procedure for new materials is considered using the example of the German regulations Formula Student Rules 2018. The results of testing samples made of PCM for a three-point bend and a break in the seatbelt attachment point are given.

Resistance spot welding is the most important method in the industry of self-supporting or monocoque body joinery because of its automation, its speed, the flexibility of welding parts with...

The search for rational and effective design options is a very good motivation for research in the construction industry. In particular, the construction of inter-floor ceiling is one of the most important elements of any building or structure, and its cost is approximately 20-30% of the total volume of all construction and installation work. Therefore, one of the problems faced by the designer is the choice of the most efficient floor covering, including in terms of efficiency. The vast majority of loads are transmitted to the framework, walls and foundations through the overlap, the actual weight of which can reach up to 70% of the total vertical static load, therefore the search for new constructive solutions for the creation and study of lightweight types of overlays, which will reduce the constant component of the load, remains relevant. Given the constructive complexity of the facilitated effective forms of overlap, the question of adapting existing methods for assessing the bearing capacity for the engineering calculation of such structures is important. The article describes a brief overview of existing studies of multilayer structures and ceilings with void inserts. The engineering methodology for calculation of bearing capacity of multilayer and claydite monocoque (with void-forming inserts) of slabs of overlappings, with their bullying in four corners is given. The bearing capacity of multilayer boards was checked for strips 250 mm wide in the middle of the extreme contour, where the maximum moments are in operation. To determine the bearing capacity of monocoque floor slabs, their calculated section was reduced to a tread section. The calculation of the considered slabs is based on the deformation technique, taking into account the nonlinear diagram of "tension-deformation" for concrete and two-line for reinforcement based on the actual physical and mechanical characteristics of materials, in accordance with the current normative documents, in particular DSTU B V.2.6-156: 2010. The comparison of theoretical calculation results with the performed experimental researches of multilayer and monocoque floor slabs is given. Graphically depicted designs and design schemes for the obstruction of prototype samples. It is suggested to use a coefficient of efficiency Kef, which allows to evaluate the efficiency of such structures compared with the classical reinforced concrete and choose the most optimal variant, which is reflected on the example of the test plates.